Money from the employees' fund at the Eurasian Natural Resources Corporation (ENRC) is alleged to have been used to send the son of a police chief in Kazakhstan, where the company mines for iron ore, to college 6,000 miles away in the United States.

It is claimed money was removed from ENRC's subsidiary SSGPO to finance the education of the son of Kazakh regional police commander, Bulat Baizhasarov, at Michigan State University.

Tuition fees for international students at the university start at more than $62,000 (£38,700) a year, with housing, insurance and other expenses adding a further $26,000 to the annual cost.

Mr Baizhasarov's son enrolled at the university two years ago, at a time when his father was based in the same region of Kazakhstan as ENRC's iron ore operation SSGPO.

The allegations of the money being siphoned off from the employees' fund, designed to assist with the education of workers' family members, is at the heart of an internal investigation at ENRC being overseen by the Serious Fraud Office into the activities of the embattled FTSE mining giant in Kazakhstan.

As well as being a senior police official, Mr Baizhasarov is reported to be co-author of a book entitled The Method of Disclosure of Contract Killings. On some official state websites, he also carries the title major general.

The investigation at ENRC is being carried out by the London office of US law firm Dechert on behalf of the company's audit committee. It was prompted by a whistleblower reporting allegations to the SFO.

When details of the investigation first emerged, it was alleged lawyers that handled the work had met with obstruction from SSGPO employees, with documents being destroyed and electronic data falsified.

The latest revelation comes as ENRC is trying to rebuild its battered image.

Boardroom disagreements last year led to two non-executive directors, former GlaxoSmithKline chairman Sir Richard Sykes and banker Ken Olisa, being removed. Mr Olisa later described the company as "more Soviet than City". In February, chairman Johannes Sittard was replaced by Mehmet Dalman.

There have also been allegations of corruption at ENRC's copper mining activities in the Democratic Republic of Congo that have been the subject of internal investigation.

A source close to ENRC confirmed the company's educational fund was being investigated but refused to confirm or deny the names of those involved.

He said: "A whistle-blowing scheme throws up numerous initial submissions which the company is required to investigate. The vast majority are not issues at all and on the relatively rare occasions when there is something further to investigate, the teams do so thoroughly with appropriate sanctions."

The SFO has pointed out that it has not itself opened an official investigation into ENRC.

"We encourage all companies within the scope of the Bribery Act to be looking at their corporate culture and their adequate procedures," it said.